Leatherbound notebook with the crest of the Somerville family on the cover, used by John Byron Somerville, circa 1811-1842. It contains notes on the organisation of the Admiralty, different duties, shipboard routines, his career as a naval officer and the services of his father Captain Philip Somerville (1763-1817). There are tables of numerical details relating to ships' boats, anchors, rigging and navigation.

A loose postcard shows a portrait of his father. There is also a receipt for consolidated annuities, relating to stock purchased by his father using his share of the prize money from French vessels captured during his command of HMS NEMESIS (1780), dated 16 February 1804.